Regex match is not greedy

I am trying to get the pid of my process using Expect using the regex pidof service\\r\\n(\\d+)

It seems that if the service is running and a pid is returned, Expect is able to find it.
But if the service is not running, pidof returns empty so this regex doesn't work.

I changed the regex to pidof service\\r\\n(\\d*) but then it won't find the pid at all and simply returns the string

pidof service

It seems the issue could be that the first line of the incoming string pidof service\r\n would match that regex and Expect returns success and won't process further ?

No se nombra ningún archivo fuente, prueba ni punto de entrada. Empieza por localizar el manejo de Expect y regex, y después reproduce los casos pidof service\r\n para un servicio en ejecución y uno ausente; se considera terminado cuando el comportamiento de coincidencia previsto queda cubierto por una prueba de regresión.